The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2000-270745 filed on Sep. 6, 2000, the entire contents thereof are hereby incorporated by reference.
1. Field of the Invention
The present invention is directed to the arrangement of an engine intake system and a housing box of a motorcycle.
2. Description of Background Art
In some motorcycles, an engine and a housing box are arranged under a seat, for example, as set forth in a scooter type motorcycle. For a motorcycle of this type, there has been known, for example, Japanese Patent No. 2525573 publication entitled xe2x80x9cAir Cleaner Case for a Scooter Type Vehiclexe2x80x9d (hereinafter referred to as xe2x80x9cprior artxe2x80x9d).
In the aforementioned prior art, as shown in FIG. 2 of Japanese Patent No. 2525573, an air cleaner case 29 is arranged at the rear of an engine body 25 (the numerals used in this description are the numerals as set forth in the publication), chambers 41 and 42 are arranged in front of the engine body 25. The chamber 42 is connected to the air cleaner case 29 through a connecting tube 37. The chamber 41 is provided integral with the chamber 42, and an intake port of the engine body 25 is connected to the chamber 41 through a carburetor 27.
Further, in the aforementioned prior art, as shown in FIG. 1 of the publication, a power unit 13 includes a power transmission device incorporated in the engine that is mounted on a body frame 2 under a tandem seat 24 so as to be able to swing up and down.
In the aforementioned prior art, preferably, the engine intake systems such as the air cleaner case 29 and the chambers 41 and 42 are of a relatively large capacity in order to sufficiently exhibit the performance of the engine body 25.
In a scooter type motorcycle as set forth in the aforementioned prior art, a housing box, not shown, is often arranged under the tandem seat 24. Preferably, the housing box has a large capacity. However, the space for arranging things under the seat is limited. When the large capacity engine intake systems and the large capacity housing box are arranged under the seat, the tandem seat 24 is unavoidably raised in order to provide the space for arranging the elements. The tandem seat 24 cannot be raised or lowered simply due to the foot-landing performance.
It is therefore an object of the present invention to provide a technique capable of increasing the capacity of an engine intake system or the capacity of a housing box without increasing the height of the seat.
For achieving the aforementioned object, there is provided a motorcycle in which a crank case, an engine with a cylinder extended forwardly from the crank case, and a housing box are arranged under a seat. An intake passage extends rearwardly from an upper part of the cylinder. An air chamber is arranged above the crank case and is connected to an intake port of the intake passage. The housing box is arranged rearwardly of the air chamber. An air cleaner is arranged sideways of the housing box, and the air cleaner and the air chamber are connected by a communication path.
The cylinder extends forwardly from the crank case, a space above the crank case can be secured. The air chamber, the housing box and the air cleaner are arranged in the surplus space. The housing box is arranged to be rearwardly of the air chamber. The air cleaner is arranged in the surplus space to be sideways of the housing box. Further, the surplus space above the cylinder is utilized to extend the intake passage rearwardly from above the cylinder, and the air chamber is connected to the intake port of the intake passage. The air cleaner is connected to the air chamber by the communication path.
As described above, the engine intake system including the air cleaner, the communication path, the air chamber and the intake passage, and the housing box can be arranged effectively making use of the surplus space under the seat.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.